Atheist John Gray argues in the Guardian that atheists who think science alone can support their preferred system of morality are fooling themselves:
It’s probably just as well that the current generation of atheists seems to know so little of the longer history of atheist movements. When they assert that science can bridge fact and value, they overlook the many incompatible value-systems that have been defended in this way. There is no more reason to think science can determine human values today than there was at the time of Haeckel or Huxley [who argued for eugenics based on science]. None of the divergent values that atheists have from time to time promoted has any essential connection with atheism, or with science. How could any increase in scientific knowledge validate values such as human equality and personal autonomy? The source of these values is not science. In fact, as the most widely-read atheist thinker of all time argued, these quintessential liberal values have their origins in monotheism….
It’s impossible to read much contemporary polemic against religion without the impression that for the “new atheists” the world would be a better place if Jewish and Christian monotheism had never existed. If only the world wasn’t plagued by these troublesome God-botherers, they are always lamenting, liberal values would be so much more secure. Awkwardly for these atheists, Nietzsche understood that modern liberalism was a secular incarnation of these religious traditions….
To be sure, evangelical unbelievers adamantly deny that liberalism needs any support from theism…. Canonical liberal thinkers such as John Locke and Immanuel Kant may have been steeped in theism; but ideas are not falsified because they originate in errors. The far-reaching claims these thinkers have made for liberal values can be detached from their theistic beginnings; a liberal morality that applies to all human beings can be formulated without any mention of religion. Or so we are continually being told. The trouble is that it’s hard to make any sense of the idea of a universal morality without invoking an understanding of what it is to be human that has been borrowed from theism. The belief that the human species is a moral agent struggling to realise its inherent possibilities – the narrative of redemption that sustains secular humanists everywhere – is a hollowed-out version of a theistic myth. The idea that the human species is striving to achieve any purpose or goal – a universal state of freedom or justice, say – presupposes a pre-Darwinian, teleological way of thinking that has no place in science. Empirically speaking, there is no such collective human agent, only different human beings with conflicting goals and values. If you think of morality in scientific terms, as part of the behaviour of the human animal, you find that humans don’t live according to iterations of a single universal code. Instead, they have fashioned many ways of life. A plurality of moralities is as natural for the human animal as the variety of languages.
As Gray says, “It’s not that atheists can’t be moral – the subject of so many mawkish debates. The question is which morality an atheist should serve.” And that is the problem. Too many atheists still don’t understand the extent to which their moral views are influenced by theism, and therefore they still don’t understand the consequences of banishing that theism.